The mayor’s plan to lift the cellphone ban in city schools will doom the small industry that stores the devices for just a buck a day — but students are buzzing about the extra cash they’ll have in their pockets.

The owner of two Urban Cell Trucks — which keep students’ phones and other electronics outside schools in Manhattan and The Bronx — said he knew the cottage industry was risky business when he bought it in 2013.

“I knew it was a gamble,” said Michael Perez, who operates his blue truck outside the Norman Thomas HS complex on East 33rd Street in Manhattan and stores as many as 300 phones a day.

“I heard six months in that schools could start allowing cellphones. I wasn’t worried because I didn’t think it would happen.”

Perez said while the job was “boring,” the cash in hand made for a decent living.

The Post reported in 2012 that the cellphone-storage industry raked in $4.2 million annually.

On Wednesday, Mayor de Blasio and Schools Chancellor Carmen Fariña announced the ban was ending on March 2, pending approval by the Department of Education’s Panel for Educational Policy.

It will then be up to principals to set policies for their individual schools. They’ll have three student options: store the devices in backpacks or another location during the school day, allow them to only be used during lunch or in designated areas or allow phones in some or all classrooms for instructional purposes.

Fariña said there would be a strict “misuse it, you lose it” policy that could result in phones being yanked for a month — with returns made only to parents.

“I think that levels the ante and also lets the parent know, look we tried to give them the freedom, they didn’t use it the right way, both of you are responsible from here on in,” Fariña said.

The end of the ban — long opposed by many parents who said it cut off essential communication during commutes to and from school and in the event of emergencies — was cheered by ­students.

“I’ve wasted too much money,” said Kyle Brown, 17, a senior at Murray Hill Academy, one of three schools housed in the Norman Thomas complex. “That’s $182 a year.”

For other students trying to make ends meet, the added cash will go a long way.

“I’ll save the money I used to store my phone for college,” said Ezmeel Ali, 19, a senior at Unity Center for Urban Technologies, another school in the complex.

Yes Lyons, 18, another Unity senior, said he’ll feel much safer having his phone on him.

“I have asthma and now if I have an asthma attack, I can call my mom,” Lyons said.